# 一：编写函数，（函数执行的时间是随机的） # import time # import random # def fun1(): # time.sleep(random.randrange(1, 3)) # print(random.randrange(1, 3)) # fun1() # 二：编写装饰器，为函数加上统计时间的功能 # import time # import random # def timer(func): # # func = fun1 # def wrapper(): # star_time = time.time() # func() # stop_time = time.time() # print('执行时间：%s' % (stop_time - star_time)) # return wrapper # @timer # def fun1(): # time.sleep(random.randrange(1, 3)) # print('welcome to the page') # fun1() # 三：编写装饰器，为函数加上认证的功能 # import time # import random # def check(func): # ''' # 修饰器：增加认证功能！ # :return: # ''' # def wrapper(*args,**kwargs): # usrname=input("Please input your name: ").strip() # pwd=input("Please input your pwd: ").strip() # if usrname == "ling" and pwd == "123": # print("Login successful!") # func(*args,**kwargs) # else: # print("Login error!") # return wrapper # @check # def name(usr): # ''' # 函数执行时间是随机的。 # :return: # ''' # time.sleep(random.randrange(3,6)) # print("%s,welcome to the page!" %(usr)) # name("ling") # 四：编写装饰器，为多个函数加上认证的功能（用户的账号密码来源于文件），要求登录成功一次，后续的函数都无需再输入用户名和密码 # 注意：从文件中读出字符串形式的字典，可以用eval('{"name":"egon","password":"123"}')转成字典格式 # db='db.txt' # login_status={'user':None,'status':False} # def auth(auth_type='file'): # def auth2(func): # def wrapper(*args,**kwargs): # if login_status['user'] and login_status['status']: # return func(*args,**kwargs) # if auth_type == 'file': # with open(db,encoding='utf-8') as f: # dic=eval(f.read()) # name=input('username: ').strip() # password=input('password: ').strip() # if name in dic and password == dic[name]: # login_status['user']=name # login_status['status']=True # res=func(*args,**kwargs) # return res # else: # print('username or password error') # elif auth_type == 'sql': # pass # else: # pass # return wrapper # return auth2 # # @auth() # def index(): # print('index') # # @auth(auth_type='file') # def home(name): # print('welcome %s to home' %name) # index() # home('egon') # 五：编写装饰器，为多个函数加上认证功能，要求登录成功一次，在超时时间内无需重复登录，超过了超时时间，则必须重新登录 # import time,random # user={'user':None,'login_time':None,'timeout':0.000003,} # # def timmer(func): # def wrapper(*args,**kwargs): # s1=time.time() # res=func(*args,**kwargs) # s2=time.time() # print('%s' %(s2-s1)) # return res # return wrapper # # # def auth(func): # def wrapper(*args,**kwargs): # if user['user']: # timeout=time.time()-user['login_time'] # if timeout < user['timeout']: # return func(*args,**kwargs) # name=input('name>>: ').strip() # password=input('password>>: ').strip() # if name == 'egon' and password == '123': # user['user']=name # user['login_time']=time.time() # res=func(*args,**kwargs) # return res # return wrapper # # @auth # def index(): # time.sleep(random.randrange(3)) # print('welcome to index') # # @auth # def home(name): # time.sleep(random.randrange(3)) # print('welcome %s to home ' %name) # # index() # home('egon') # 六：编写下载网页内容的函数，要求功能是：用户传入一个url，函数返回下载页面的结果 # from urllib.request import urlopen # # def get(url): # return urlopen(url).read() # print(get('https://www.baidu.com')) # 七：为题目五编写装饰器，实现缓存网页内容的功能： # 具体：实现下载的页面存放于文件中，如果文件内有值（文件大小不为0），就优先从文件中读取网页内容，否则，就去下载，然后存到文件中 # import requests # import os # cache_file='cache.txt' # def make_cache(func): # def wrapper(*args,**kwargs): # if not os.path.exists(cache_file): # with open(cache_file,'w'):pass # # if os.path.getsize(cache_file): # with open(cache_file,'r',encoding='utf-8') as f: # res=f.read() # else: # res=func(*args,**kwargs) # with open(cache_file,'w',encoding='utf-8') as f: # f.write(res) # return res # return wrapper # # @make_cache # def get(url): # return requests.get(url).text # res=get('https://www.baidu.com') # print(res) # 扩展功能：用户可以选择缓存介质/缓存引擎，针对不同的url，缓存到不同的文件中 # import requests,os,hashlib # engine_settings={ # 'file':{'dirname':'./db'}, # 'mysql':{ # 'host':'127.0.0.1', # 'port':3306, # 'user':'root', # 'password':'123'}, # 'redis':{ # 'host':'127.0.0.1', # 'port':6379, # 'user':'root', # 'password':'123'}, # } # # def make_cache(engine='file'): # if engine not in engine_settings: # raise TypeError('egine not valid') # def deco(func): # def wrapper(url): # if engine == 'file': # m=hashlib.md5(url.encode('utf-8')) # cache_filename=m.hexdigest() # cache_filepath=r'%s/%s' %(engine_settings['file']['dirname'],cache_filename) # # if os.path.exists(cache_filepath) and os.path.getsize(cache_filepath): # return open(cache_filepath,encoding='utf-8').read() # # res=func(url) # with open(cache_filepath,'w',encoding='utf-8') as f: # f.write(res) # return res # elif engine == 'mysql': # pass # elif engine == 'redis': # pass # else: # pass # # return wrapper # return deco # # @make_cache(engine='file') # def get(url): # return requests.get(url).text # # # print(get('https://www.python.org')) # print(get('https://www.baidu.com')) # 八：还记得我们用函数对象的概念，制作一个函数字典的操作吗，来来来，我们有更高大上的做法，在文件开头声明一个空字典，然后在每个函数前加上装饰器，完成自动添加到字典的操作 # route_dic={} # # def make_route(name): # def deco(func): # route_dic[name]=func # return deco # @make_route('select') # def func1(): # print('select') # # @make_route('insert') # def func2(): # print('insert') # # @make_route('update') # def func3(): # print('update') # # @make_route('delete') # def func4(): # print('delete') # # print(route_dic) # 九 编写日志装饰器，实现功能如：一旦函数f1执行，则将消息2017-07-21 11:12:11 f1 run写入到日志文件中，日志文件路径可以指定 # 注意：时间格式的获取 # import time # time.strftime('%Y-%m-%d %X') # import time # import os # # def logger(logfile): # def deco(func): # if not os.path.exists(logfile): # with open(logfile,'w'):pass # # def wrapper(*args,**kwargs): # res=func(*args,**kwargs) # with open(logfile,'a',encoding='utf-8') as f: # f.write('%s %s run\n' %(time.strftime('%Y-%m-%d %X'),func.__name__)) # return res # return wrapper # return deco # # @logger(logfile='aaaaaaaaaaaaaaaaaaaaa.log') # def index(): # print('index') # # index()